The packaging of flowable solid particulate material (FSPM) represents a challenge when using the air-impermeable plastic bags. When filling and sealing the bag with FSPM (such as flour or cement powder, for example), a substantial amount air may be entrained within the bag interior. If this residual air is not released by a valve or perforation of the bag, the volume of the bag is unnecessarily large—making storage, stacking, transport, and handling of the FSPM bag difficult. The residual air within an FSPM-filled bag also compromises the stability of bags stacked upon each other, such as on pallets, for example. The presence of residual air in the FSPM-filled bag also reduces the number of bags that can be transported on a forklift, for example.
Perforation of the film results in water penetration for outdoor storage and deterioration of film physical properties. These pose great challenges for paper to plastics conversion for powdery goods.
Conventional attempts to remove residual air form FSPM-filled bags have shortcomings. Vacuum sealing FSPM-filled bags is disadvantageous because this process invokes a high capital cost for vacuum equipment which is compounded by constant maintenance costs to keep the vacuum equipment operational. For example, the filters of the vacuum sealing device require constant cleaning to avoid damage to the vacuum sealing device.
The use of perforated plastic films for the bag fail to adequately protect the FSPM from water penetration. Perforated plastic films are particularly problematic in outdoor storage environments where exposure to rain, humidity and other ambient moisture enters the perforations and degrades the FSPM content. Water penetration yields to agglomeration, degradation, decay, and deterioration of the flowable solid particulate material.
Consequently, the art recognizes the need for improved packaging systems for the filling and storage of flowable solid particulate material.